Is there a limit on the number of merits than can be sent in one hit?
Yes, 50. It's also the limit that can be sent to the same person in one month.
Sending merits to the same person seems like supporting of a multiply account. If I would be a moderator such case would awake a lot of doubts and I would put a red trust on both.
Without coming up with a Merit Ponzi scheme I'll doubt I'll be ranking up anytime soon.
I am in the same position, man. There are a lot of users like us, unluckys.